碳化养护混凝土生命周期环境影响的评估  

Life Cycle Assessment of Environmental Impacts of CO_(2)-cured Concrete

作　　者：郭冰冰 储嘉 王艳 牛荻涛[1] GUO Bingbing;CHU Jia;WANG Yan;NIU Ditao(School of Civil Engineering,Xi’an University of Architecture and Technology,Xi’an 710055,China;School of Materials Science and Engineering,Xi’an University of Architecture and Technology,Xi’an 710055,China)

机构地区：[1]西安建筑科技大学土木工程学院,西安710055 [2]西安建筑科技大学材料科学与工程学院,西安710055

出　　处：《材料导报》2024年第24期107-116,共10页Materials Reports

基　　金：国家自然科学基金(52341803);深圳市承接国家重大科技项目的产业化应用研究(CJGJZD20220517141806015)。

摘　　要：碳化养护能够实现混凝土对CO_(2)的高附加值利用与封存,因此本工作开展碳化养护对混凝土生命周期环境影响的研究。结合文献中的试验研究,建立碳化养护混凝土生命周期环境影响的数据集,进而开展碳排放的计算。基于蒙特卡洛模拟方法,研究原材料碳排放系数不确定性对环境净效益计算结果的影响。结果表明,水泥生产过程和混凝土养护过程的碳排放是影响碳化养护混凝土环境效益的关键因素。120组数据集中有21组会产生正的环境净效益,其余99组会产生负的环境净效益。增加碳化养护时间和气压能够提升混凝土的CO_(2)封存量,但碳化设备能耗的提升导致碳化养护混凝土生命周期碳排放过高。碳化养护时间过长、养护气压过高或混凝土力学性能降低皆为碳化养护混凝土环境净效益为负的原因。根据碳化养护对混凝土生命周期环境影响的计算结果,建议采用常压条件下的碳化养护,其养护时间控制在6 h内。Considering that CO_(2)curing for concrete can achieve high-value utilization and sequestration of CO_(2),the life cycle environmental impact assessment of CO_(2)-cured concrete was studied here.Based on experimental investigations in existing literatures,datasets of the life cycle environmental impacts for CO_(2)-cured concrete were established,and then the carbon emissions were calculated.Based on the Monte Carlo simulation method,the uncertainty analysis of the influence of carbon emission coefficient of raw materials on the calculation results of environmental net benefit was studied.The results indicated that carbon emissions from the production process of cement and the curing process of concrete are key factors affecting the environmental benefits of CO_(2)-cured concrete.The results of uncertainty analysis showed that,among the 120 datasets,21 datasets would produce positive environmental net benefits,and the other 99 datasets would produce negative environmental net benefits.Increasing CO_(2)curing time or gas pressure could enhance the amount of CO_(2)captured by concrete,but it could also increase the energy consumption of carbonation equipment,leading to excessive carbon emissions during the production process of CO_(2)-cured concrete.Excessive CO_(2)curing time,high pressure and the resulted reduction of mechanical properties of concrete can lead to negative environmental net benefits of CO_(2)-cured concrete.Thus,based the calculation results in this work,it is recommended to use atmospheric pressure CO_(2)curing for a duration of less than 6 h.

关 键 词：碳化养护混凝土 生命周期评价 环境效益 养护制度 蒙特卡洛模拟 

分 类 号：TU375[建筑科学—结构工程]